To study the metabolism of N-acyl derivatives of amino acids and related compounds with particular reference to synthesis and regulation of metabolism by N-acetyl glutamate and especially to the control of ammonia metabolism in health and diseased states. More specific aims are: 1) physiological role of acetyl glutamate in the mitochondria and synthesis of acetyl glutamate and related derivaties, 2) mechanism of carbamyl-P synthesis with special emphasis on the role of acetyl glutamate and glutamine-dependent carbamyl-P synthetase activity in animal tissues, and 3) protein and other modification reactions by carbamyl phosphate with special emphasis on uremia and carbamylation of proteins particularly brain following administration of cyanate and the turnover of the modified proteins.